The subject matter disclosed herein relates generally to imaging systems, and more particularly to a method and system for performing correction and reconstruction of medical images.
Multi-modality imaging systems scan using different modalities, for example, Computed Tomography (CT), Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), and Single Photon Emission Computed Tomography (SPECT). During operation, image quality may be affected by various factors. One such factor is patient motion. Another factor is inaccurate attenuation correction between images acquired using two different imaging modalities caused by the patient motion.
Accordingly, at least one known PET-CT system utilizes data that is generated by the CT system to generate an attenuation correction of the PET scan data. Specifically, a plurality of emission attenuation correction factors are derived from CT data that is generated during a CT scan, wherein the CT system is specifically configured to generate data to be utilized for the CT attenuation correction factors. More specifically, the CT information is utilized to generate an attenuation map, which may then be applied to attenuation correct PET or SPECT emission information.
In PET imaging, for example, an accurate quantitative reconstruction of the tracer distribution requires taking into account the attenuation and scatter of the photons by the tissues. Scatter correction requires accurate attenuation estimation. Respiratory motion can have a negative effect on the accuracy of a generated attenuation map. Certain respiratory affected areas of a scanned subject may be susceptible to an attenuation correction mismatch between the CT attenuation correction factors and the PET emission information. Reducing this mismatch with improved technologies is needed to improve accuracy and image quality.